1. Technical Field
The present invention relates to an integrated circuit for satellite signal reception.
2. Related Art
Various receivers for receiving satellite signals for positioning have been developed. One request for such receivers is that a time (TTFF: Time To First Fix) from measurement start to initial measurement is made very short (high speed) even in a so-called weak electric field environment. However, the signal intensity of the satellite signal for positioning is originally weak. Thus, in order to capture and track the satellite signal for positioning in the weak electric field environment, the reception sensitivity needs to be enhanced. One known technique for improving reception sensitivity is to prolong the time for integrating the results of correlation processing.
However, when the integration time is prolonged, the preparation for positioning calculation takes much time, and consequently, the TTFF becomes long. Thus, shortening the TTFF even in the weak electric field environment requires fulfilling two contrary demands.
As a technique for shortening the TTFF, US Patent Application Publication No. 2003/0081660 discloses a correlation process that is performed at a higher speed than a speed of receiving a signal. In this way, the correlation process is virtually parallelly performed.
Another request for the receiver of the satellite signal for positioning is miniaturization. However, the core part of the receiver of the satellite signal for positioning includes one or plural integrated circuits, and is manufactured as a part of the entire apparatus obtained by the user. Accordingly, a problem in miniaturization of the receiver is how to make the integrated circuit as small as possible.